<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

</body>
</html>
<script type="text/javascript">
    'use strict';
    // let a = 1, b = 2, c = 3;
    // let [a,b,c] = [1,2,3]; // 以数组赋方式定义3个变量：a, b, c，值分别为1，2，3
    // console.log(a, b, c); // 1 2 3

    let arr = ["a","b"];
    let [a,b,c] = arr; // 声明3个变量：a,b,c，并给a赋值1，b赋值2，c没有赋值，所以，c的值为undefined
    console.log(a, b, c); // a b undefined
</script>